Hi Rob;
Interesting. I'm not sure, but it looks like they've used spectroscopic and photometric data modelling to calculate the masses of the Primary and Secondary.
I don't have access to their paper, but the Figures and Tables Index is
here.
Table 1 gives the results.
From the
abstract, I'd say that they've confirmed the primary as a cepheid, used the standard candle method of accurately determining the mass of the primary. The eclipse with the secondary seems to then have been used to check the accuracies of the respective models.
Not sure though. Interesting, none-the-less.
Cheers